1. Field of the Invention
The present invention relates to a vasoactive intestinal polypeptide (hereinafter referred abbreviately to as "VIP") analogue, namely a novel polypeptide with biological activities as in "vasoactive intestinal polypeptide", and use thereof.
The VIP analogue according to the invention can be used as an effective ingredient For various medicines, for instance an agent for curing asthma, anaphylaxis, hyperpiesia, impotence and the like, as well as a hair tonic.
2. Related Arts
The VIP is one of peptide hormones and firstly isolated and refined by Said and Mutt in the year of 1970 from a subfraction, when secretin was extracted from a tissue of porcine upper small intestine. In 1974, a primary amino acid structure of the VIP has been made apparent as consisting of 28 amino acids and it has been considered that It belongs to a glucagonsecretin family.
Structure of the native VIP (SEQ ID NO:1) ##STR1##
It has been confirmed that the VIP presents in nervous systems in addition to the digestive canal to develop various biological activities, for instance a relatively high vasodilating-hypotensing action; atonic action on smooth muscle; accelerating action of intestinal juice secretion, pancreatic juice and bile secretions, and tear secretion; suppressing action of gastric juice secretion; accelerating action of glycogen decomposition; accelerating action of various pituitary hormone secretions; increasing action of blood flow into penis; vasodilating action of bronchus; anti-allergic action; antitumor action; growing action of hair and others.
Following patent literatures have been issued in Japan on the VIP, VIP analogues and use thereof.
a) Jap. Pat. No. Sho 56 128721(A), Anti-allergic agent; PA1 b) Jap. Pat. No. Sho 62-16429(A), Acceleration of tear secretion; PA1 c) Jap. Pat. No. Sho 62-116595(A), Anti-tumor and ulcer agent; PA1 d) Jap. Pat. No. Sho 62-246595(A), Bronchodilatation agent and hypotensor; PA1 e) Jap. Pat. No. Sho 63-1799892(A), Preparation of VIP-HCl unstable to acids; PA1 f) Jap. Pat. No. Sho 64-83012(A), An agent for growing hairs; PA1 g) Jap. Pat. No. Hei 1-296996(A), Hypotensor; and PA1 h) Jap. Pat. No. Hei 2-76821(A), External preparation for curing impotence. PA1 His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-X-Ala-Val-L ys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-Y PA1 wherein X is a residue of amino acid other than methionine (Met); and Y is homoserine, homoserine-lactone, amidized homoserine, a residue reacted homoserine-lactone with a primary alkyl amine having carbon atoms not exceeding 20, or an optional polypeptide chain and containing an amidized homoserine at C-terminal,
Among of those biological activities, the VIP has been expected as the drugs for curing an asthma and impotence, by utilizing the bronchodiliatating action and the atonic action on smooth muscle of corpus cavernosum, respectively. A structural characteristic of the VIP lies in that there is an amide structure at C-terminal, which has been estimated as an indispensable matter for developing the biological activities of VIP.
For obtaining a polypeptide having an amide structure at C-terminal in accordance with conventional and widely accepted techniques which utilize a expression microorganism such as Escherichia coli, in general, it is required to separate and purify an expressed polypeptide and then to treat the polypeptide with use of a special C-terminal amidation enzyme. However, such an enzymatic method can not be said as that suitable for industrial scale production, since such enzyme is expensive and yield of the objective polypeptide becomes low.
Although there is no relation to the VIP in question, the inventors have found that on motilin analogues accelerating a peristalsis of intestines, those with homostrine or homoserine-lactone at C-terminal show biological activities in same level with or higher than the native motilin, and they have proposed a process for preparing such motilin analogues with a reasonable cost and in a large amount [Jap. Pat. Appln. No. Sho 64 (1989) 286, corresponding to a part of U.S. Ser. No. 07/459236 and EP-03 78 078(A1)].
Further, it has been reported that a chemically synthesized VIP analogue--methionine residue at 17th position of the native VIP being substituted with leucine or norleucine--shows biological activities similar to the native VIP [said Jap. Pat. No. Sho 62-246595(A)]. Therefore, it has been considered that the methionine residue at 17th position has almost no influence on useful activities of the VIP.
Hitherto, it has been considered as quite difficult to provide the VIP or VIP analogues with a reasonable price and in a large amount, since according to the prior arts, there is no way other than utilizing a synthetic process therefor or an extraction method thereof from an animal tissue, and the former requires troublesome operations due to that the VIP is polypeptide consisting of 28 amino acids, and takes a relatively long period of time in its chemical synthesis and for purifying the same, and the latter is restricted on availability of the raw material and requires troublesome purification procedures.
Further, the technique utilizing so-called "Biotechnology" can not be said as--convenient method--, since it requires a special technique for the amidation at C-terminal, as referred to hereinbefore.